Understanding the possible mechanism(s) by which the DASH dietary pattern lowers blood pressure will potentially enhance the value of this dietary intervention by elucidating the conditions under which it will be most effective, identifying target populations, examining its impact on vascular health beyond blood pressure, and enhancing the investigators' understanding of the interactions among diet, blood pressure and vascular function. In addition, results of this study may help to identify additional therapeutic targets. Therefore, the overall goal of the proposed study is to determine the mechanism(s) by which the DASH dietary pattern lowers blood pressure by using a controlled feeding design.